As a result of the recent energy crisis, more and more attempts are being made to collect the heat given off by the sun so that that collected heat can be put to various uses where other forms of energy have been used in the past.
For the most parts, the recently developed solar heat collecting arrangements as well as their predecessors are extremely complicated and require many different parts, most of which require frequent maintenance. As a result, the cost of both setting up and operating the prior art arrangements is extremely high. This high cost is even harder to justify in light of their poor efficiency which is limited by the fact that much of the collected sunlight is lost as heat energy before it can be put to good use. As a general rule, standard heat collecting systems operate at an unacceptable 35% efficiency due to their large surface areas undesirably radiating off much of the collected heat energy.
The present invention relates to a solar heat collecting system which is generally much less complicated and less expensive than conventional systems. At the same time, the solar heat collecting system of the present invention operates above the standard 35% efficiency point by minimizing the surface areas and heat losses.
The solar heat collecting system of the present invention comprises a lense which is pointed at the sun having a focal length for focusing sunlight at a flat reflective surface. The flat reflective surface is spaced from the lense by half of its focal length and is positioned to reflect the sunlight back at the lens and to bring sunlight to a focal point. Located at this focal point is a symmetrical funnel means having an inwardly tapered reflective inner surface for funnelling the sunlight to light piping means. The light piping means carries the sunlight still in the light energy form to a boiler where it is ultimately converted to thermal energy. The thermal energy collected at this point is then put to efficient use.
As a result of the construction of the present invention, both the flat reflective surface and the funnelling means may be totally enclosed against the entrance of dirt, dust, moisture, etc., which essentially eliminates the requirement of constant maintenance to these components. Therefore, both the cost of setting up and operating the present invention structure is much lower than prior art arrangements. In addition, its efficiency relative to its cost is considerably greater than standard arrangements due to the fact that the collected sunlight is maintained in a light energy form until it reaches the boiler which greatly reduces inefficient heat losses.